Companies and the like have built a computer system for assisting their employees in performing tasks in business. An example of such a computer system is a workflow system in which the temporal order of tasks is defined in advance. Once a preceding task is completed, the system sends to a terminal a message that informs a person, who is expected to be in charge of a subsequent task, about performing the subsequent task.
Examples of the related art include Japanese Laid-open Patent Publication Nos. 2005-110205, 2004-54855, and 2005-275476.